Crepe fabric and method of preparing same



Patented Aug. 10, 1937 UNmmj TAT-E Z CREPE rABnrcANo Ma'rnonor mils,

ING SAME Will am Whitehead, Cumberlandr Md assignor i I l to Celanese Corporation of America,:a corporation of Delaware N0 vDrawing; Application February 2, 1934, "seriainoqzoaasi V a 4 Claims. c1. iii-2)],

This invention relates to the treatment and production of textile fabrics made from yarn havor other fabrics requiring a yarn containing a high degree of twist. Other objects of the invention will appear from the following detailed description.

By employing this invention processing steps heretofore necessary to produce a yarn sumciently twisted to form a heavy crepe fabric are eliminated. Also yarn that has been exposed to the atmosphere for long periods of time'may be commercially twisted to crepe yarn.

According to my invention I twist yarn while the same is soft i. e. the yarn contains solvents and/ or plasticizers, with or without the additional 7 may be accomplished by lowering the spinning plastifying action of steam. Thus the twist may be imparted to the yarn at the spinning cabinet prior to total evaporation of the solvent or the yarn may be plasticized or it may be softened by subjectingit to the mild action of solvents such as a dilute vapor or solution of a solvent or to the action of a mild solvent or a swelling agent.

This invention is applicableto yarns or filaments of any thermoplastic derivative of cellulose and especially the organic derivatives of cellulose such as the organic esters or ethers of cellulose. Also there may be employed the nitro organic esters of cellulose. Examples of organic esters of cellulose are cellulose acetate, cellulose formate, cellulosepropionate and cellulose butyrate, while examples of organic cellulose ethers are methyl cellulose, ethyl cellulose and benzyl cellulose. The invention is also applicable to yarns containing cotton, wool, sill: or other fibres that are mixed with thermoplastic derivatives of cellulose.

Under the term. yarns or filaments are included, threads, assemblies or bundles of a number of continuous filaments which may be in parallel relationship or which may betwisted together, artificial bristles, straws, short lengths of staple fibres, or yarn spun from such stable fibres. Although the invention is applicable to all types of yarns or filaments it is especially applicable to yarns consisting of several substantially continuous filaments. g

The yarns or filaments preferably of organic esters of cellulose may be formed in a normal manner by either the wet or dry method of spin- .ticularly advantageous in this respect.

ning andtreated'according to this invention as they leave or while still in; the spinning cabinet to a twisting actionand withsteam to par ially set the'twist. At this stage in the formation of the yarn the same contains sufficient solvent to be maintained in 'a softened and pliable'pondition. The amount of solvent, whichi 'm'ay be a simple substance or a complex mixture such as acetone, a mixture of dichlorethylene and alcohol, a mixture of benzene and acetone or a mixture of alcohol and acetone, will vary somewhat according to the conditions of spinning suchas the temperature, the speed o fjspinnlng, the rate of exhaust ing the solvent vapors fromthe spinning cabinet and so on. 7 Usually in current spinning practice the amount of solvent residual in' the threadwill be from 8 to 20% on the dry weight of thethread. It is of advantage in some cases to increase the amount of residual solvent in the thread particularly'where very high twists are required to obtain very heavy'cre'p'ing actions in the fabrics. This temperature or reducing the spinning cabinet length. Further, high boiling solvents, for example, ethyl lactate, ethyl oxybutyrate, the ethers of the'glycols and similar high boiling solvents. Another method of increasing the solvent of the yarn as spunis to add substantial quantities of material, which retard the evaporation of the solvent, to the solution from which the-materials are to be spun. The fatty alcohols are par- Under average dry or evaporative methods of spinning, 10 to of cetyl alcohol added to the spinning solution, will approximately double the amount of residual solvent in the yarn.

Thus this soft yarn may be twistedv as it is formed by reducing the spinning feed rateto a, few meters a minute and maintalningthe spindle speed of a cap spinning takeup bobbin at between 10,000 and 11,000 revolutions per minute. If desired the yarn may alsobe passedthrough steam just prior to its reaching the cap spinning device. The yarn may be treated with steam by passing it through a container or jacket containing steam or the steam may be applied to the yarn by means of a jet of steam blowing across the yarn and the excess removed by a suction cap on the opposite side. A device for applying steam to yarn, such as disclosed in U. S. application S. No. 703,426 may be used.

In place of treating the yarn at the spinning cabinet the yarn may be formed into packages with little or no twist and stored for considerable periods of time. This yarn, prior to imparting over, but if the fabric is aged, preferably at elevated temperatures to reduce the ethyl oxya twist thereto, is subjected to solvents in a mild form to soften it. The yarn may be softened by placing it in a humidor containing a substantial amount of a solvent vapor or, the yarn may be passed, duringa winding operation and preferably a the winding operation during which the twist is imparted to the yarn, through an enclosed space I containing a mild solvent or a solvent in dilute concentration. The solvent may be applied to the yarn from solution or as a vapor. As an thereto may be dilute phenol, dilute acetone,g pyridine, alcohol, glycol, ethers and esters of glycol and, ethyl ether of ethylene glycol.

.The yarns and filaments may contain besides the organic derivatives of cellulose base a plasticizer and especially those plasticizers that have an increased softening action upon the cellulose i derivatives at elevated temperature. Examples of such plasticizers are diethyl phthalate, dibutyl phthalate, triacetin,; etc,

When the presence of the solvent in theme;- ment might interfere with dyeing processes and produce effects not desired, such as a heavy deluster. by precipitation of the materials in the dye bath, the solvent may be removed by washing at'a temperature which will not produce such.

eifect or in a bath which does not produce such effects. Thus tetrachlorethane in the yarn may produce a, deluster if the yarn is treated in a normal aqueous dye bath at normal dyeing temperatures. -However,athe fabric may be washed with benzolfirst and dried to remove the solvent and the ,benzol and then dyed in a normal manner. Or again, a substantial quantity of ethyl oxybutyrate will produce a deluster when the yarn is treated in a normal scour bath at 85 C. or

butyrate content to 4% or less, subsequent normal scouring does not produce deluster.

Besidesthe plasticizers the yarns or filaments may contain efiect materials such as dyes or lakes,

fire retardants-pigments,filling vmaterials and lubricants. Examples of fire retardants are beta chlornaphthalene, triphenyl phosphate and tri-f cresyl phosphates Examples of. lubricants are glycols and glycerols, olive oil, teaseed oil and petroleum Jelly. Examples of filling materials are powdered metal, powdered metal oxides and carbonates, powdered organic substances that when added to the material change its light absorption' properties and like material.

.inch.

The benzol may be re-.

of the twist i The amount of crepe twist imparted to the yarn is preferably over turns per inch or it may be or more, say 80, or turns per As description notifies a limitation the following example is given. v

Yarns and filaments are formed by extruding ,a solution of cellulose acetate in acetone through vsuitable orifices into an evaporative atmosphere that removes the acetone such that only between 8 and 20% is left in the yarn or filaments. These yarns or filaments are twisted as they leave the spinning cabinet by maintaining the feed rate at a few meters per minute and winding and twisting them onto a cap spinning device whose spindle speed is between 10,000 to11,000 revolutions per minute. Other methods of winding and twisting the yarn at the spinning cabinet maybe employed for example ring and flyer methods. a

Alternatively yarns which havebeenexposed to .evaporative atmospheric conditions. such that their residual solvent has been reduced torbelo w 8% may be twisted bytreating ,them with sumcient solvent to again make themsoft and then twisting them in the presence or absence of steam during a winding operation. The yarns by either rnethodgmay be given a high degree of twist say ,75 or'above turns per inch.

The twisted yarns may ormay not be sizedand may then be woven in a normal manner into a fabric which when treated according to' commo methods will'produce a crepe fabric. i Having described my invention, whatIx desire to secure by Letters Patent is: a i

1. The method of preparing crepe yarns containing'individual filaments 'of organic derivatives of cellulose which comprises twisting yarn containing a solvent and, during theactual insertion of the twist in the yarn, subjecting the yarn to steam. i

2. The method of preparing crepe yarns containing individual filaments ofcellulose acetate which comprises twisting yarn containing a solvent and, during the actual insertion of the twist in the yarn, subjecting theyarn to steam. V

3. The method'of preparing crepe ya-r'ns contalningindividual filaments of organic derivatives of cellulosev which: comprises adding a solvent to the yarn, twisting the yarn and, during the actual insertion of the twist in the yarn,"subjectingjthe yarn to steam.

4. The method of preparing crepe-yarns containing' individual niament Of cellulose ,acetate which comprises adding a solvent to the yarn, twisting the yarn and, (lining the actual insertion n the yarn, Isubjectin'grthe yarn to steam, v -V WILLIAMWHI'I'EHEAD. 

